Questions tagged [odds-ratio]
A measure of association between two binary variables equal to the odds of a 'positive' outcome in 1 variable divided by the odds in the other. The OR ranges (0, infinity). It has a strong connection to logistic regression.
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Calculating odds ratio in Multiple select choice question analysis
I have a multiple response categorical variable (MRCV) and a single response categorical variable (SRCV). Respondents in my survey were presented with 6 choices (6 barriers to access an application) ...
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How do I get an odds ratio using Mcnemar in R? [duplicate]
I have pre and post test data evaluating the effectiveness of a lesson about how to help friends who are being bullied. I am trying to see if more students know how to help a friend being bullied ...
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How do I get an odds ratio with McNemar's test?
I have pre and post test data evaluating the effectiveness of a lesson about how to help friends who are being bullied. I am trying to see if more students know how to help a friend being bullied ...
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Expectation of odds ratio
I am conducting a simulation with 3 variables:
X: binary, experiment/control indicator
Y: binary, outcome
C: covariates
Logistic regression is used to estimate ...
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How to calculate OR (odd ratio) if one of groups is “0” in a case-control study in R?
I am new to R I am using epicalc package to calculate Odds Ratio.
I have this data
Real values
...
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160 views
Where is my mistake in this definition of Bayes Factor?
From "The Bayesian Choice" by Christian P. Robert.
The definition of the Bayes factor is given to be the ratio of the posterior probabilities of the null and the alternative hypothesis over the ratio ...
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How does one compute the posterior odds ratio between two models
Apologies if this question has been asked before but I couldn't find anything that matched my problem.
I have some astronomy based data sets and wish to find which of three models fits the data the ...
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3answers
78 views
Computation and Interpretation of Odds Ratio with continuous variables with interaction, in a binary logistic regression model
Question
A binary logistic regression model has been fitted, with the following output;
...
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2answers
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Odds ratio? Can someone help me with what these stats from a paper mean?
this paper I'm reading is on MAOA and violent offenders. From what I understand, an odds ratio of 1.71 means that the violent offenders were almost 2x likely to exhibit the low activity MAOA compared ...
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Conditional logistic regression on matched data with replacement
I'm using 1 to 5 matching on my data with replacement, where each treatment is paired to at most 5 control units with the possibility of one control unit being assigned to more than one treatment.
...
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1answer
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Adjusted odds ratio question
I have a question about adjusted odds ratios for matched data. Let's assume that we have a binary variable that we want to determine the odds ratios for (let's say smoking or not smoking, this is the ...
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2answers
122 views
17 Week Coin Flip Contest - Calculate Probability/Odds For Each Individual To Have The Winning Count Of “Heads”
I'm new to statistics, like WAY new. So green, in fact, I'm scarcely pushing (0,1,0) in the RGB color model.
I'm presently the recordkeeper for our office's 17-week "Coin flip pool". As of right now, ...
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226 views
Is meta-analysis of odds ratios essentially hopeless?
In a recent paper Norton et al. (2018)$^{[1]}$ state that
Different odds ratios from the same study cannot be compared when the
statistical models that result in odds ratio estimates have ...
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Can we compare odds ratio from one factor to another factor?
For example ${\rm logit}(\pi)=\beta_1 \cdot x_1+ \beta_2 \cdot x_2$, then I find that the odds ratio of $x_2$ is 27, and the odds ratio of $x_1$ is 1.5, can I say that $x_2$ has a more significant ...
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When to adjust for oversampling
This may be a question that is too broad for a single answer, so I'll attempt a narrowing of sorts with the below restrictions:
Response is a binary outcome
Split full data set into a ...
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A paradox: Indication of difference in stratum-specific odds ratio, but failing to reject null hypothesis in Tarone's test
I have been asked to answer a question on association between arsenic exposure and death from lung cancer in smokers and non-smokers.
This is a case-control study. Cases are workers who died of ...
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1answer
31 views
Difficulty understanding contingency table and logistic regression coefficient
I have the following contingency table
D not-D
E 980 122
not-E 2420 6439
where D may stand for disease, and E for exposure.
This leads to the ...
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1answer
21 views
Difference in logits to difference in probabilities
a) Is there any way to prove that you cannot compute a probability difference when you know a logit difference?
b)In general, is there some acceptable way to convert distances in logodds space to ...
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1answer
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Odds ratio, Meta-analysis
I have the following for the data for the meta-analysis:
OR , standard errors, logged OR , variance of logged OR
I have generated a forest plots first using "OR" with "variance of logged OR" using ...
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Reporting values from generalized estimating equations with dependent variables having over two values
I am using SPSS for generalized estimating equations including rather skewed variables. Now I am just curious as to how I should interpret and report my results. I have seen several papers using GEE ...
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1answer
62 views
Betting with odds
I have a game where I can bet on two teams:
One team has odds $1.7$
The other has $1.5$
I understood that the one that pays off $1.5$ has an higher probability of victory, so it pays less. But how ...
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3answers
641 views
logit - interpreting coefficients as probabilities
I seem to be missing some vital piece of information. I am aware that the coefficient of logistic regression are in log(odds), called logit scale. Therefore to interpret them, ...
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Does an odds ratio estimate from a matched case-control study approximate an odds ratio from a usual case-control study?
And therefore if the odds ratio from the matched case-control study relates to a rare disease, does this also approximate a risk ratio?
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Interpretation of Overlapping p-value = 0 and Odss ratio = Inf
I would like to conduct an enrichment analysis between two lists using GeneOverlap package in R. I am comparing gene IDs from each list, and there is no NAs in there.
This is the code I'm using:
<...
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1answer
29 views
Odds ratio and Risk ratio disagree?
Is it possible for the odds ratio and the risk ratio for a variable to disagree? For example - an odds ratio >1 and risk ratio <1?
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Predicted probabilities for multiple categories of a categorical variable
I'm developing predicted probabilities for hypothetical cases in my glm (binary logit). I have a four category categorical predictor where "Single" is the reference category and "MOU", "JPA" and "AD" ...
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Odds-ratio difference
The odds-ratio denotes a relative effect measure.
If person A has \$100 and person B has \$150, the OR of the
money person B has relative to person A is 1.5. This can be
interpreted as person B ...
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1answer
39 views
Math formula to reproduce a plot comparing Relative Risk to Odds Ratios
I'm trying to reproduce Figures 1, 2 and 3 in this paper (notice that clicking on the FIGURES/TABLES tab is enough to see the plots - no need to sign up or create an account), simply to understand how ...
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1answer
153 views
Does confidence interval for odds ratio assume log-normal distribution?
The formula floating around for calculating 95% confidence interval of an odds ratio is:
e^(log(OR) ± 1.96 x sqrt(1/a + 1/b + 1/c + 1/d))
Does one need to ...
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3answers
468 views
Why is odds ratio an estimate of relative risk?
This link says
In epidemiological terms, the odds ratio is used as a point estimate of the relative risk in retrospective studies.
I understand that odds ratio is calculated in case control ...
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model checking in bayespolr
I'm trying to run an ordered logistic regression with the bayespolr function from the arm package. My response variable is categorical with three outcomes. I've got a few questions about this ...
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Odds ratio formulation of bayes rule for joint conditional distribution
I'm wondering how we can express the marginal conditional odds $O_{h|e}$ when $h$ and $e$ are part of a large joint distribution $P(h,e,z)$.
I know that Bayes rule can be re-expressed in terms of ...
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1answer
140 views
Convert odds ratio to Cohen's d, taking rate of prevalence into account
I am familiar with the generic formula to convert OR to Cohen's d. However, I get the very strong impression from a relatively recent paper (https://www.tandfonline.com/doi/abs/10.1080/...
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How to assess predictive validity of a variable on the outcome?
I am looking to assess the predictive validity of two measures (M1 and M2) on a binary outcome. After constructing my model, do I just calculate odds ratios and compare the odds ratios for the two ...
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1answer
68 views
Crude odds ratio
I came across following definition of crude odds ratio in binary logistic regression:
Crude odds ratio is when you have only one independent variable
And also I heard:
Crude odds ratio is when ...
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How are these odds created?
I've always been a bit baffled by how Vegas creates sports odds. Not so much the process of how did the oddsmakers decide that Option A has odds of X/Y (that obviously is fairly subjective and not ...
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1answer
269 views
Rule of thumb for log odds ratios effect size interpretation
Let's start by fitting a logistic model:
fit <- lme4::glmer(vs ~ wt + (1|gear), data=mtcars, family="binomial")
summary(fit)
The output is the following:
<...
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1answer
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Comparison of two odds ratios: Take 2
I would like to test the difference of two odds ratios given the following R-output.
To do so, I would need to take the difference of the log odds and obtain the standard error (outlined here: ...
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1answer
160 views
Binary logistic regression: Interpreting odds ratio vs. comparing predictive probabilities
Consider the following logistic regression:
...
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1answer
134 views
Odds Ratio and gene mutations association
I have a simple (yet to me still trivial) problem to submit to you.
I have a dataset of a group of patients affected by a disease, for which the presence of several genes mutations was inferred.
Each ...
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Why is a variable with a comparatively smaller odds ratio statistically significant (when the larger OR is not)? [closed]
I have two predictors in a binary logistic regression model, where both variables are on the same scale (standardized). I find it puzzling that the variable with a smaller OR is significant at p <. ...
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1answer
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The difference between the logits of two probabilities is the logarithm of the odds ratio? Correct/Incorrect?
I was reading a Wikipedia article on the logit function, and I came across the following in the definition section:
If $p$ is a probability, then $p/(1 - p)$ is the corresponding odds; the logit of ...
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260 views
Interpreting Odds Ratio for a Continuous Variable in a Fractional Logit Model
I am using proportion to data to measure the effect of several variables on on lameness level (continuous variable, given as % of herd lame). Ideally I would have the counts to model it as over-...
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1answer
192 views
why is the log transform of the odds ratio in meta analysis not explicitly described in methods
As we know when analysing the odds ratios in meta analysis we use the log transform of the OR to get the effect size.
I think most papers/analyses do this but the log transformation never seems to be ...
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2answers
45 views
Compare odds ratios that are above and below 1
I am testing a logistic regression model that has two continuous IVs in SPSS. The DV is of course binary. IV-1 has an odds ratio above 1 and IV-2 has an odds ratio below 1. I understand what these ...
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1answer
55 views
Meta-analysis of Odds Ratios and Asymmetric Confidence Intervals
I've come across a series of association studies that report odds and asymmetric confidence intervals. The standard meta-analytic techniques I've used assume symmetrical confidence intervals to ...
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1answer
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Which regression analyses to use? Please help!
Before we begin, my knowledge around anything "statistics" related is minimal so any help is appreciated.
I am studying whether performing a surgery at night is safe vs during the day.
I would like ...
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1answer
223 views
Odds ratio for continuous dependent variable by regression analysis
Can the odds ratio be calculated for a continuous dependent variable using logistic regression? If yes, kindly explain the procedure in SPSS. Further, can we apply logistic regression to an dependent ...
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1answer
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Calculating Odds Ratio within Regression (in R)
I am calculating a regression model for passing a test, where the independent variables are Age, Pencils and Animals. I am looking for Odds ratios, I'm very confused why it isn't working...
Lets's ...
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1answer
70 views
understanding the relationship between two binary variables
I want to answer the following question: what is the relationship between binary variable A and binary variable B?
In my case variable A is a marker for the presence of the flu, and variable B is a ...
